Liver fibrosis assessed by transient elastography is independently associated with albuminuria in the general United States population.

Background: Nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are frequent and progressive conditions that share traditional risk factors: obesity, type 2 diabetes and hypertension.

Aims: To evaluate whether an independent relationship exists between liver steatosis and fibrosis and different CKD phenotypes.

Methods: Cross sectional study based on data from the 2017-18 cycle of the National Health and Nutrition Examination Survey. Vibration controlled transient elastography (VCTE) was performed in a US representative sample allowing the simultaneous assessment of liver steatosis (CAP: controlled attenuation parameter) and fibrosis (LSM: liver stiffness measurement) and their relationships with CKD phenotypes (albuminuria and reduced estimated glomerular filtration rate, eGFR).

Results: 4746 adult participants had a complete VCTE exam. Prevalence of liver steatosis and significant fibrosis was 33.7% (95%CI: 30.9-36.6%) and 8.9% (95%CI: 7.5-10.5%), respectively. Logistic regression analysis showed that liver fibrosis, but not steatosis, was associated with albuminuria (OR 2.19, 95%CI: 1.49-3.20) and albuminuria or reduced eGFR (OR 2.18, 95%CI: 1.59-3.00) also when adjusted for age, sex, ethnicity, BMI, diabetes, blood pressure categories, glycated haemoglobin, use of renin-angiotensin-aldosterone system blockers and CAP.

Conclusions: In the general US population liver fibrosis assessed using VCTE is associated with CKD, and in particular with the albuminuric phenotype, regardless of traditional risk factors.